高碱煤燃烧过程细颗粒物排放特性

摘要

The amount of Zhundong coal is huge.The high content of alkali and alkaline earth metal (AAEM) in Zhundong coal results in more fine particulate matter during its combustion.In this paper,the emission of fine particulates from AAEM rich coal in Zhundong and AAEM poor coal in Zhunnan was investigated in a drop tube furnace.The size distribution,concentration and composition of the particulates were measured.The distribution of Na,K,Mg,Ca,Fe in fine particulates and their effects on the generation of fine particulates were obtained.The results show that the fine particulates from AAEM rich coal combustion mainly consist of sulfates and the oxides of AAEM.The amount of fine particulates from burning AAEM poor coal decreased significantly.Co-firing of AAEM rich coal with AAEM poor coal had an obviously synergistic effect of reducing the fine particulates emission.Ca and Fe played an important role in PM10 reduction during blended coal combustion.%准东煤储量巨大,但由于其碱金属和碱土金属含量较高,准东煤燃烧时会生成更多的细颗粒物.在一维沉降炉上对新疆准东地区高碱煤、准南低碱煤及混煤燃烧过程细颗粒物的排放特性进行了研究,对其燃烧生成的颗粒物粒径分布、生成浓度、元素组成进行了分析,获得了高碱煤中Na,K,Mg,Ca,Fe在细颗粒物中的分布及对细颗粒物生成特性的影响.结果显示:高碱煤燃烧生成的细颗粒物主要由Na,K,Mg,Ca的硫酸盐和氧化物组成;低碱煤燃烧产生的细颗粒物量明显减少;同时发现了低碱煤的掺烧有明显降低细颗粒物生成量的协同效应,Ca,Fe在混烧降低PM10过程中起到了重要作用.